Northrop F-89 Scorpion
|Formation of three F-89Ds of the 59th Fighter Squadron, Goose Bay, Labrador.|
|First flight||16 August 1948|
|Primary users||United States Air Force
Air National Guard
|Unit cost||US$801,602 (F-89D)
The Northrop F-89 Scorpion was an early American jet-powered fighter aircraft designed from the outset as an all-weather interceptor. Though its straight wings limited its performance, it was among the first USAF jet fighters with guided missiles, and notably the first combat aircraft armed with air-to-air nuclear weapons (the unguided Genie rocket).
Design and development 
The Scorpion stemmed from a 1945 United States Army Air Forces Army Air Technical Service Command specification ("Military Characteristics for All-Weather Fighting Aircraft") for a jet-powered night fighter to replace the P-61 Black Widow. Bell Aircraft, Consolidated-Vultee, Douglas Aircraft, Goodyear, Northrop and Curtiss-Wright all submitted proposals.
Northrop submitted four different designs, prepared by Jack Northrop's team, including a radical flying wing but settled on the N-24, a slim-bodied aircraft with a cantilevered mid-mounted wing and two Allison J35 turbojet engines with afterburners. It was to have radar and a crew of two, with an armament of four 20 mm (.79 in) cannon in a unique trainable nose turret. One of the unusual aspects of the design was the use of Northrop's "Deceleron", a clamshell-style split aileron which could function as a dive brake (like the SBD Dauntless dive bomber's perforated-panel flaps did) or flap as needed on landing approach, that could be accommodated in the slim wing design. The unique feature added to the prototype during development was to become a Northrop trademark, still used today on the B-2 Spirit. Contracts for two prototypes were issued in December 1946, while Douglas with their XF3D-1 Skyknight and Curtiss for their XF-87 Blackhawk prototypes also were awarded development contracts.
The initial XP-89 prototype made its first flight on 16 August 1948, with test pilot Fred C. Bretcher at the controls. For much of the testing period, Curtiss's entry had been the front-runner for the contract, but in a competition fly-off with its main competitors, the Northrop design proved superior. Other USAF interceptors such as the F-94 Starfire and F-86 Sabre had been adapted from day fighter designs.
Operational history 
Production was authorized in January 1949, with the first production F-89A flying in September 1950. It had AN/APG-33 radar and an armament of six 20 mm (.79 in) T-31 cannons with 200 rpg. The swiveling nose turret was abandoned, and 300 US gal (1,100 l) fuel tanks were permanently fitted to the wingtips. Underwing racks could carry 16 5 in (127 mm) aerial rockets or up to 3,200 lb (1,455 kg) of bombs.
Only 18 F-89As were completed, which were mainly used for tests and trials, before the type was upgraded to F-89B standard, with new avionics. The type entered service with the 84th Fighter-Interceptor Squadron in June 1951. These had considerable problems with engines and other systems, and soon gave way to the F-89C. Despite repeated engine changes, problems persisted, compounded by the discovery of structural problems with the wings that led to the grounding of the F-89 and forced a refit of 194 -A, -B, and -C models.
The major production model was the F-89D, which first flew 23 October 1951 and entered service in 1954. It removed the cannon in favor of a new Hughes E-6 fire control system with AN/APG-40 radar and an AN/APA-84 computer. Armament was two pods of 52 2.75 in (70 mm) "Mighty Mouse" FFAR rockets, for a total of 104. A total of 682 were built.
Proposed re-engined F-89s, designated F-89E and F-89F, were not built, nor was a proposed F-89G that would have used Hughes MA-1 fire control and GAR-1/GAR-2 Falcon air-to-air missiles like the Convair F-106 Delta Dart.
The subsequent F-89H, which entered service in 1956, had an E-9 fire control system like that of the early F-102 and massive new wingtip pods each holding three Falcons (usually three semi-active radar homing GAR-1s and three infrared GAR-2s) and 21 FFARs, for a total of six missiles and 42 rockets. Problems with the fire control system delayed the -H's entry into service, by which time its performance was notably inferior to newer supersonic interceptors, so it was phased out of USAF service by 1959.
The final variant was the F-89J. This was based on the F-89D, but replaced the standard wingtip missile pod/tanks with 600 gal (2,271 l) fuel tanks and fitted a pylon under each wing for a single MB-1 Genie nuclear rocket (sometimes supplemented by up to four conventional Falcon air-to-air missiles). The F-89J became the only aircraft to fire a live Genie as the John Shot of Operation Plumbbob on 19 July 1957. There were no new-build F-89Js, but 350 -Ds were modified to this standard. They served with the Air Defense Command, later renamed the Aerospace Defense Command (ADC), through 1959 and with ADC-gained units of the Air National Guard through 1969. This version of the aircraft was extensively used within the Semi Automatic Ground Environment (SAGE) air defense system.
A total of 1,050 Scorpions of all variants were produced.
Accidents and incidents 
On 30 August 1952, Major Donald E. Adams, a Korean War ace was killed along with his radar operator at a Detroit air show, when a wing tore off of their Scorpion.
- First prototype, powered by two 4,000 lbf (17.8 kN) Allison J-35-A-9 engines.
- Second prototype. Fitted with more powerful (5,100 lbf (22.7 kN) dry, 6,800 lbf (30.3 kN) with reheat) J-35-A-21A engines and revised, pointed nose with cannon armament.
- First production version, eight built. Fitted with revised tailplane and six cannon armament.
- F-89As converted into drone control aircraft.
- Second production version with upgraded avionics. 40 built.
- F-89Bs converted into drone control aircraft.
- Third production version with more powerful engines (5,600 lbf (25.0 kN) dry, 7,400 lbf (32.0 kN) reheat J-35-A-21 or -33). 164 built.
- Conversion of one F-89B to test new avionics and armament of F-89D.
- Main production version which saw deletion of the six 20 mm (.79 in) cannons in favor of 104 rockets in wing pods, installation of new Hughes E-6 fire control system, AN/APG-40 radar and the AN/APA-84 computer. This new system allowed the use of a lead-collision attack in place of the previous lead-pursuit-curve technique. A total of 682 built.
- One off prototype to test the Allison YJ71-A-3 engine (7,000 lbf (31.2 kN) dry thrust, 9,500 lbf (42.4 kN) with reheat), converted from F-89C.
- Proposed version with new fuselage and wings and J71 engines, never built.
- Proposed version equipped with Hughes MA-1 fire control and GAR-1/GAR-2 Falcon air-to-air missiles, never built.
- Modified F-89D to test features of F-89H. Three converted.
- Version with E-9 fire control system, six GAR-1/GAR-2 Falcon missiles and 42 Folding Fin Aircraft Rockets (FFAR). 156 built.
- Conversion of F-89D with underwing hardpoints for two MB-1 Genie nuclear armed rocket and four Falcon missiles, and carrying either the standard F-89D rocket/fuel pod or pure fuel tanks. A total of 350 were converted from F-89Ds.
Aircraft on display 
- 53-2494 - home base of the 158th Fighter Wing, Vermont Air National Guard, Burlington Air National Guard Base, Vermont.
- 53-2547 - 120th Fighter Wing of the Montana Air National Guard at Great Falls Air National Guard Base, Great Falls International Airport, Montana.
- 52-1911 (painted as 53-2509) - National Museum of the United States Air Force, Wright-Patterson Air Force Base, Dayton, Ohio. This aircraft was the last F-89 remaining in service when it was transferred to the Museum from the Maine Air National Guard in July 1969.
Specifications (F-89D) 
Data from Scorpion with a Nuclear Sting 
- Crew: 2
- Length: 53 ft 9½ in (16.40 m)
- Wingspan: 59 ft 8½ in (18.20 m)
- Height: 17 ft 6 in (5.33 m)
- Wing area: 606 ft² (56.30 m²)
- Empty weight: 25,194 lb (11,428 kg)
- Loaded weight: 37,190 lb (16,869 kg)
- Max. takeoff weight: 42,241 lb (19,161 kg)
- Powerplant: 2 × Allison J35-A-35 afterburning turbojets
- Dry thrust: 5,440 lbf (24.26 kN) each
- Thrust with afterburner: 7,200 lbf (32.11 kN) each
- Maximum speed: 635 mph (552 knots, 1,022 km/h) at 10,600 ft (3,200 m)
- Ferry range: 1,366 mi (1,188 nm, 2,200 km)
- Service ceiling: 49,200 ft (15,000 m)
- Rate of climb: 7,440 ft/min (37.8 m/s)
- 104× 2.75 in (70 mm) "Mighty Mouse" folding-fin aerial rockets
- 16× 5 in (127 mm) aerial rockets on underwing racks or
- Bombs: 3,200 lb (1,500 kg)
See also 
- Aircraft of comparable role, configuration and era
- Avro Canada CF-100
- Lockheed F-94 Starfire
- North American F-86D Sabre
- Sud Aviation Vautour
- Yakovlev Yak-25
- Related lists
- Knaack 1978, p. 93.
- Knaack 1978, p. 96.
- Davis and Menard 1990, p. 4.
- Air International July 1988, p. 46.
- Davis and Menard 1990, p. 5.
- Knaack 1978, p. 85.
- Air International July 1988, pp. 47–48.
- Knaack 1978, p. 87.
- Knaack 1978, pp. 88–89.
- Air International August 1988, pp. 88–89.
- "The Crash of the YF-89D: (aka - 'The Jones Site')." Check-Six.com, 11 June 2012. Retrieved: 12 May 2013 On January 31, 1957, Roland E. Owen F-89 had a midair collision with a DC-7b. DC-7 crashed into a school yard. Following the collision, Curtiss Adams, the radarman aboard the eastbound twin-engine F-89J Scorpion, was able to bail out of the stricken fighter jet and, despite incurring serious burns, parachuted to a landing onto a garage roof in Burbank, breaking his leg when he fell to the ground. The fighter jet’s pilot, Roland E. Owen, died when the aircraft plummeted in flames into La Tuna Canyon in the Verdugo Mountains http://en.wikipedia.org/wiki/Pacoima_aircraft_accident.
- Angelucci and Bowers 1987, p. 370.
- Ramirez, Charles E. "Selfridge museum to restore fighter jet." The Detroit News, 18 April 2012. Retrieved: 18 April 2012.
- Air International August 1988, p. 92.
- Angelucci and Bowers 1987, p. 372.
- Air International August 1988, pp. 89–90.
- Air International August 1988, p. 90.
- "F-89 Scorpion/49-2457." nampa.id.us, 5 June 2007. Retrieved: 25 September 2011.
- "F-89 Scorpion/53-2463." Robins Air Force Base. Retrieved: 25 September 2011.
- "F-89 Scorpion/53-2494." Warbird Registry. Retrieved: 9 October 2012.
- "F-89 Scorpion/53-2519." Planes of Fame Museum. Retrieved: 25 September 2011.
- "F-89 Scorpion/53-2536." EAA AirVenture Museum. Retrieved: 28 August 2010.
- "F-89 Scorpion/53-2547." Aeroweb. Retrieved: 9 January 2013.
- "F-89 Scorpion/53-2610." Eglin Air Force Base. Retrieved: 25 September 2011.
- "F-89 Scorpion/53-2674." Pima Air & Space Museum. Retrieved: 25 September 2011.
- "F-89 Scorpion/53-2677" Minnesota Air Guard Museum Retrieved: 25 September 2011.
- "F-89 Scorpion/54-0298." Warbird Registry Retrieved: 9 October 2012.
- "F-89 Scorpion/54-0322." Hill Aerospace Museum Retrieved: 9 October 2012.
- "F-89 Scorpion/52-1856." Warbird Registry Retrieved: 9 October 2012.
- "F-89 Scorpion/52-1896." New England Air Museum. Retrieved: 9 October 2012.
- "F-89 Scorpion/52-1911." National Museum of the USAF Retrieved: 9 October 2012
- "F-89 Scorpion/52-1927." Castle Air Museum. Retrieved: 25 September 2011.
- "F-89 Scorpion/52-1941." Peterson Air and Space Museum. Retrieved: 25 September 2011.
- "F-89 Scorpion/52-1949." March Field Air Museum. Retrieved: 25 September 2011.
- "F-89J Scorpion/52-2129." Hampton Air Power Park. Retrieved: 25 September 2011.
- "F-89 Scorpion/52-2453." Heritage Flight Museum. Retrieved: 25 September 2011.
- Air International July 1988, p. 49.
- Angelucci, Enzo and Peter Bowers. The American Fighter. Yeovil, UK: Haynes Publishing Group, 1987. ISBN 0-85429-635-2.
- Davis, Larry and Dave Menard. F-89 Scorpion in action (Aircraft Number 104). Carrollton, Texas: Squadron/Signal Publications Inc., 1990. ISBN 0-89747-246-2.
- Isham, Marty J. and David R. McLaren. Northrop F-89 Scorpion: A Photo Chronicle. Atglen, Pennsylvania: Schiffer Military History, 1996. ISBN 0-7643-0065-2.
- Jenkins, Dennis R. and Tony R. Landis. Experimental & Prototype U.S. Air Force Jet Fighters. North Branch, Minnesota: Specialty Press, 2008. ISBN 978-1-58007-111-6.
- Kinsey, Bert, F-89 Scorpion, Detail and Scale Vol. 41. Waukesha, Wisconsin: Kalmbach Publishing, 1992. ISBN 1-85310-630-5
- Knaack, Marcelle Size. Encyclopedia of US Air Force Aircraft and Missile Systems, Volume 1, Post-World War Two Fighters, 1945-1973. Washington, D.C.: Office of Air Force History, 1978. ISBN 0-912799-59-5.
- "Scorpion with a Nuclear Sting: Northrop F-89". Air International, Vol. 35, No. 1, July 1988, pp. 44–50. Bromley, UK: Fine Scroll. ISSN 0306-5634.
- "Scorpion with a Nuclear Sting: Northrop F-89—Part Two". Air International, Vol. 35, No. 2, August 1988, pp. 86–92. Bromley, UK: Fine Scroll. ISSN 0306-5634.
- Swanborough, F. Gordon and Peter M. Bowers. United States Military Aircraft Since 1909. London: Putnam, 1963. ISBN 0-87474-880-1.
- United States Air Force Museum Guidebook. Wright-Patterson AFB, Ohio: Air Force Museum Foundation, 1975.
|Wikimedia Commons has media related to: F-89 Scorpion|
- Joe Baugher F-89 pages
- "First Look Inside The USAF F-89 Scorpion Fighter," Popular Science 1951 article with cutaway of F-89 with original six 20 mm cannon nose, article at bottom of page
- (1957) T.O. 1F-89D-1 Flight Handbook USAF Series F-89D Scorpion Aircraft (Part 1), (Part 2)